Bump grpcio-tools from 1.56.0 to 1.56.2 in /test/environment/grpc (#472)

Bumps [grpcio-tools](https://github.com/grpc/grpc) from 1.56.0 to 1.56.2.
- [Release notes](https://github.com/grpc/grpc/releases)
- [Changelog](https://github.com/grpc/grpc/blob/master/doc/grpc_release_schedule.md)
- [Commits](grpc/grpc@v1.56.0...v1.56.2)

---
updated-dependencies:
- dependency-name: grpcio-tools
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

test/environment/grpc/requirements.txt

@@ -2,4 +2,4 @@ grpcio==1.56.2
 grpcio-health-checking==1.56.0
 grpcio-reflection==1.56.0
 grpcio-testing==1.56.0
-grpcio-tools==1.56.0
+grpcio-tools==1.56.2